When powered on, most computers refer to firmware to determine the location of a binary image of an operating system (OS) and/or hypervisor/virtual machine host software to be booted. Where there is more than one possible location of the OS image, the firmware can provide a prioritized list of locations. The highest-priority location is checked first; if an OS image is found there, the operating system is booted from that image. If no suitable OS image is found at a listed location, the next location in the list is checked.
Some data centers and other large computer systems use a storage area network to connect many computers to many storage devices. So that each computer does not have to search through all available storage devices for an OS image, each computer and each disk storage unit can be configured to interact with only one or a limited number of devices. For example, each computer and each storage device comes with factory-set hardware identifiers. Each computer can be configured to interact only with storage devices having certain hardware identifiers, and each storage device can be configured to only interact with computers having certain hardware identifiers, e.g., unique world-wide names (WWNs). However, in very large computer systems, this configuration task can be unwieldy; typically, an administrator or administrative team must keep track of all the configurations to ensure everything works as intended and conflicts are avoided.
Virtual Connect technology, available from Hewlett-Packard Company, substantially eases the burden of managing storing resources for computer systems. Using this technology, storage devices can be pre-configured to work with computers with certain identifiers. To allow a computer to access a storage device, the computer can be configured with the corresponding virtual identifier. If, for example, a computer fails, its virtual identifier can be migrated to its replacement, obviating the need to reconfigure the storage device each time the computer it is assigned to is changed.
Whether a computer is configured directly or by importing data from its slot, the configuration data must identify the location of an OS image. For some BIOS (basic input-output system) firmware, the information needed is fairly limited and is generally well understood by system administrators. For example, the configuration data for storage devices, such as Fibre Channel or SAS (Serial-Attached SCSI), may need to specify a source WWN (e.g., for a host-bus adapter installed on a computer), a WWN for a disk array, and a LUN (logical unit number that identifies a section of a disk array assigned to a given computer). However, computers using more advanced and flexible EFI (extensible firmware interface) require more information, such a boot directory, boot file name, disk partition, and some EFI-specific variables. OS installers typically handle such information so that, generally, system administrators do not have ready access to this data. Thus, making Virtual Connect technology available to EFI-based computers has posed a challenge.
Herein, related art is described to facilitate understanding of the invention. Related art labeled “prior art” is admitted prior art; related art not labeled “prior art” is not admitted prior art.